The invention relates to breastshields for breastpumps.
Breastpumps are well known, and generally are comprised of breastshields (also referred to as hoods) that fit over the breast, a vacuum pump connected to the breastshield for generating an intermittent vacuum within the breastshield, and a receptacle for the milk that is pumped from the breast. Manually driven vacuum pumps are commonplace, as well as those that are driven by a motor (house current, battery, pneumatic, etc.).
The vacuum pumps of these devices intermittently generate a vacuum (or negative pressure) within the breastshield, with the breastshield covering the nipple and typically a substantial amount of the breast itself. The intermittent suction action of the pump serves to pull on and compress the breast, and thereby extract milk in an action similar to suckling. The milk so extracted ordinarily flows from the breastshield into a collection container, e.g., a bottle, for storage and later use. A breastpump of the foregoing description is shown in U.S. Pat. Nos. 4,857,051, and 4,929,229, and reference thereto may be made for further detail on breastpumps in general.
Breastshields typically have a funnel-shape, comprising a conical portion with a tubular extension, sometimes referred to as the nipple tunnel. The nipple and surrounding breast are received in the conical portion, with the nipple often extending into the tubular extension. Under vacuum, the breast is pulled further into the breastshield, ordinarily with the nipple then being pulled into the tubular extension, with the surrounding breast thereby also compressed about the nipple.
A nursing mother""s nipples may thus be forced against the wall of the nipple tunnel under vacuum. This may cause friction against the wall as the nipple moves deeper into the nipple tunnel. There can also be friction between the breast and the conical portion, as well as the nipple tunnel.
Breastshields have traditionally been made using a regularly shaped conical portion and nipple tunnel. That is, the conical portion is a geometric cone, with a smooth interior wall having a circular axial cross-section. The nipple tunnel is likewise smooth-walled, with a circular cross-section. Breastshields have also traditionally utilized a conical portion having a single slope angle (i.e., a single angle of revolution for the frustoconical part). An abrupt, and typically sharp-angled, transition is used between the conical portion and the tubular extension.
It is a principal objective of the invention to provide an improved breastshield for breastpumps. To that end, one aspect of the invention comprises a breast-receiving part, typically having a cone-shaped portion with a truncated apex forming an upstream opening in the cone, an exterior and an interior. A tubular extension, or tunnel, extends from the apex opening of the cone, ordinarily along a common longitudinal axis with the cone. The entrance of the tubular extension has an inlet proximal thereto, which communicates with the apex opening of the cone. As will be noted hereafter, other non-conical shapes for the breast-receiving part can be utilized.
In one form of the invention, the interior of the tubular extension is provided with an irregular shape, with the irregular shape preferably (but not necessarily) starting adjacent the opening of the tubular part and extending some or all of the length of the tubular extension. The interior cross-sectional shape in certain embodiments may be triangular, squarish, oval, pentagonal, and the like, all of which are non-traditional shapes (e.g., non-circular) for the nipple tunnel. In addition, or alternatively, the interior sidewall of the tubular extension may be provided with a non-circular (in radial cross-section) surface contour of, for instance, smoothly undulating peaks and valleys taking on a fluted shape. Bumps, ridges and other protuberances, most preferably fixed in shape, whether in a regular or irregular pattern, may be provided in another variant. It will be additionally noted that the foregoing non-traditional shapes and surface contours may advantageously extend into the conical (i.e., breast-receiving) part of the breastshield.
In another aspect of the invention, the inlet to the interior of the tubular extension is provided with a less abrupt transition surface from the conical portion. This transition surface between the conical portion and the tubular extension takes the form, in one embodiment, of a chamfered transition surface. In this latter embodiment, the main area of the conical portion has a first slope, with an intermediate area between the main area and the tubular extension having a second slope, with the second slope selected to provide an intermediate gradient between conical portion and nipple tunnel entrance.
It is anticipated that the foregoing non-circular contours for the tubular extension interior will have beneficial effects upon the milk expression process. In many respects, these shapes are reminiscent of various mouth and tongue positions of a baby during suckling. The aspect of the invention wherein a chamfered and therefore less abrupt transition is provided between the conical portion and tubular extension is likewise expected to have a salutary effect, at a minimum, reducing the pressure on the breast/nipple at this transition and providing a more comfortable device.
These and other aspects and advantages of the present invention will be further appreciated and understood upon consideration of the detailed description of various embodiments of the invention taken in conjunction with the drawings, in which: